温热条件下TC4钛合金板材超声振动辅助拉伸工艺研究

Study on Ultrasonic Vibration-assisted Stretching Process of TC4 Titanium Alloy Sheet under Thermal Conditions

摘要:

针对钛合金板材塑性变形能力差、成形温度高的问题，提出了温热条件下超声振动辅助成形方法，希望在温热环境条件下进一步提高钛合金板材的成形性能。本文通过200-600℃条件下的TC4板材超声振动辅助拉伸实验，分析了超声振动工艺参数对钛合金板材拉伸过程当中的工程应力-应变曲线、屈服强度、延伸率等性能指标的影响规律，并对拉伸试件显微组织及断口形貌进行分析。研究结果表明，温热拉伸过程施加合适的超声振动工艺参数，可以使TC4板材流动应力、屈服强度进一步降低，延伸率进一步提高，能够实现在温热条件下进一步提高成形性能的目的。

Abstract:

Based on the poor plasticity and high temperature required for forming of titanium alloy sheet, an ultrasonic vibration-assisted forming method under thermal conditions was proposed, which is expected to further improve the formability of titanium alloy sheets under thermal conditions. The effects of ultrasonic vibration process parameters on the engineering stress-strain curve, yield strength and elongation of titanium alloy sheet were analyzed by tensile test of TC4 sheet at 200-600℃. And the microstructure and fractography of the tensile specimens were analyzed. The results showed that superimposing ultrasonic vibration process with appropriate parameters in the thermal tensile process can further reduce the flow stress and yield strength of TC4 sheet and improve the elongation, and it can achieve the purpose of further improving the formability under thermal conditions.